Well tool



y 951 L. HARTSELL 2,562,458

WELL TOOL Filed May 21, 1945 Fisl Fie. 2

3nventor Lee Harcsell Gttornegs Patented July 31, 1951 5 j.

2,562,458 t WELL TOOL w 1 p Lee Hartsell, Houston, Tex.

Application May 21, 1945, Serial No. 594,811

4 Claims. (01. 166-230) V This invention relates to tools for cleaning screens or perforated casings at the bottom of drilled wells.

The invention provides a device which can be lowered into the well by the use of a cable and may then be operated repeatedly until the desired results are secured. The attainment of these results may be deduced from the resistance to upward motion offered by the tool.

An important advantage of .the device over prior art devices for similar purposes arises from the fact that it includes no parts which require to be set or latched. Consequently, unlike most prior art devices, it need not be withdrawn from the well between recurrent cleaning manipulations. Another advantage is that the tool is short and thus can be lowered through a crooked Well without serious difficulty.

A preferred embodiment of the invention which has been successfully used in commercial operations will now be described by reference to the accompanying drawing, in which:

Fig. 1 is a longitudinal axial section of the tool showing the parts in the positions which they assume when the tool is being lowered through liquid in the well.

Fig. 2 is a similar section showing the position assumed by the valve mechanism when the tool is being drawn upward through liquid in the well.

The body of the tube comprises a cylindrical shell 6 having its upper closed end reduced and externally threaded as indicated at I. The thread I provides means for attaching either the lower end of a sinker bar or the lower end of a string of pipe as the operator may prefer. The sinker bar is simply a heavy cylindrical member, forming a longitudinal extension of the tool. When a sinker bar is used the tool and the bar are low ered together by a cable attached to the upper end of the sinker bar. This is the simplerv and hence the preferred way of using the tool. The sole function of the sinker bar is to add whatever weight is needed to assure movement of the tool downward through liquid'in the well.

The body 6 has an offset 8 affording an in-- ternal valve seat 9, and an external shoulder I l. The lower portion l2 of the body is cylindrical but of smaller internal and external diameters than the portion 6. The lower end is externally threaded as indicated at l3. Fitting over the re-; .duced portion [2 and engaging the shoulder II is a sleeve [4. This acts as a spacer to retain against upward motion the hub of a packer or swab cup l5, which is ordinarily made of rubber 01' similar material with suitable reinforcement.

This packer is cup-like in its general form, and has an expansible rim which is rounded, as shown, to facilitate passing obstructions such as joints in the well casing or the like.

The lower hub portion of the swab cup [5 is conical or tapered externally, as indicated at [6, and is confined by a ferrule ll which has a conical socket designed to fit portion 16. The parts l4, l5 and i! are slipped over the reduced portion l2 of the body in the order stated, and are confined by the tubular lower section l8 which screws on to the threads l3 and engages the lower end of the ferrule I'i locking all the parts toether between section I8 and shoulder II. The end section i8 is tubular and forms an open ended extension of the body portion I2. This extension is externallytapered as indicated at 19, the taper serving to facilitate motion of the tool downward through the well casing.

The body 6 has two sets of apertures. The apertures of the first set, indicated at 2|, are near the upper end of the bore of the member 6. Four are indicated. The apertures indicated at 22, also four in number, are located immediately above the valve seat 9. The lower body member I8 has four radial apertures 23 as shown.

-Mounted within the portion 6 above the valve seat 9 is a floating valve member made up of two parts, 24 and 25, threaded together at 26. The upper member 24 is tubular and has an inturned flange 2'! at its upper end. This flange serves as a seat for a steel ball valve 28. The lower member 25 is tubular and is formed with a conical or tapered external valve surface 29. This has a central aperture 3! in its lower end. Aperture 3| is somewhat smaller than the bore of the member 25 so that there is an internal flange which serves as a seat for the lower end of a coil compression spring 32. The spring 32 reacts between the lower end of the member 25 and the ball valve 28. By screwing the member 25 farther into the member 24 the spring load on the valve 28 may be increased.

The tapered portion 29 is so dimensioned as to engage the seat 9 and seal therewith. The steel ball 23 acts *as a relief valve at times when the surface 29 seals against the valve seat 9 as shown in Fig. 2.

Operation The tool may be lowered into the well by attaching it to the lower end of a string of pipe, but it is preferred to attach the tool to the lower end of a cylindrical sinker bar whose upper end is attached to a cable so that the tool and sinker bar are suspended by the cable. The sinker bar furnishes the necessary weight to move the assembly down through the liquid in a drilled well whose diameter slightly exceeds the outside dimeter of the tool.

As the tool moves down the liquid will flow up through the bore of the lower section I9 and will escape through the apertures 22 and 2!. To do so it lifts the floating valve element 24-25 to a position such as that shown in Fig. 1. During the descent of the tool through the well the packer or swab cup l will be close to the walls of the well bore or casing, but need not seal closely therewith. When lowering of the tool has been completed the packer l5 should be at or near the lower end of the screen or perforated casing section to be cleaned.

The next step is to draw the tool upward. At,

that time the packer will expand and seal with the inner surface of the screen or perforated casing. The valve 2425 will move downward until the; tapered portion 29; engages. the; seat. 9-. The effect of the upward motion of the tool will be to reduce the hydraulic pressure, immediately be.- low the packer l5 and increaseI it. immediately above the packer so that solids, which may be trapped in they screen meshes or in the, perforartions of the perforated casing. will be displaced by hydraulic pressure which acts outward. in the zone above the packer and inward in the. zone below the packer. Consequently, as the tool moves upward the, screen perforations are Subjected first to hydraulic pressure acting outward and then to hydraulic pressure acting inward. The. ball 28 operates as a. relief; valve,- to, limit the differential pressure. so developed. between the spaces above; and below the packer l,5 The pressure at which. the relief valve; will open, is adjustable. It: protects the cable and also the packer against overloads. The relief valve is. needed when the columnv of liquid in the well is high. It, is set to. open at a pressure of say 500, p. s. i. With a short liquid column it. might not open. Thus it is primarily a load-limiting valve.

After the tool has been lowered it is drawn up tov the upper end of the screen. It, may then be. immediately lowered and the; cleaning operation repeated as many times asv is necessary. When the screen has been cleared, that fact will be, evidenced by a reduced resistance to upward mo.- tion.

No part of the tool needs to be manually set, so, it may operate recurrentlywithout withdrawal from the well. In addition to this the tool has the advantage that it, is short and maybe readily. lowered. in a well even though the well be rather crooked. The packer is simple in form and may readily be removed and replaced.

While one embodiment, of the invention has been described in considerable detail, the inventive concept may be incorporatedin an apparatus of different forms, and no necessary limitation to the specific structure. illustrated. is implied. The scope of the invention is defined solely by the, claims.

I What is claimed is: fll. A tool for cleaning screens or perforated casings in drilled wells, comprising in combine.

4 tion an elongated tubular body adapted to be lowered into a well, open at its lower end, and having an internal valve seat and ports leading through the walls of the body above said seat; a swab cup surrounding said body below the ports therein and having an upward extending expansible rim; a hollow check valve freely movable within the body, adapted to move downward by gravity into sealing contact with said seat, said valve comprising two axially ported members threaded together, the upper one having an internal valve seat and the lower one an internal spring seat; a relief valve within the upper member arranged to move upward to seal against the internal seat in said upper member; and a coil compression spring held under stress between said relief valve and. the spring seat in said lower member.

2. The combination defined in claim 1 in which the relief valve is of the ball type, and the two parts of the hollow check valve may be setin various adjusted positions, whereby the resistance of said ball valve to opening may be adjusted'. i Y

3. A tool for cleaning" screens or perforated casings in drilled: wells, comprising in combination an elongated tubular body adapted to be lowered into a well, open at. its. lower end, andhaving an internal valve seatv and ports leading through the walls. of the body above said seat; aswab cupsurrounding said; bodybelow. the ports therein and having, an upwardly extending expansible rim; a hollow. check valve freely movable within thebody, adapted to move downwardly by gravity into sealing contact with said seat, said valve comprising axially ported members connected' together, an internalevalve seat. in the up.- per member with a relief valvein thev upper member urged. upwardly against. the. valve, seat. by. a coil compression spring- 4. A well liner washing tool including; a tubu.-. lar mandrel member having. a. valve. seat therein and by-pass. ports; above said. seat. a. valve assembly freely movable. in. the. mandrel. above said seat. and in sealing; engagement. with said. seat to prevent downward fluid flow therethroughat pressures lesser than a predetermined: fluidpressurerandrunseatable from-.saidrvalveseat by fluid pressure exerted upwardly through. the. mandrel member permitting upward flow through, the mandrel. and valve; means within said valve as. sembly inv a fluid. passage; extending. the. length of the assembly; operable by predetermined fluid pressure acting downwardly within, the mandrel for establishing downward; flow through the asesembly.

LEE HAR'ISELL. REFERENCES CITED The following references are of record in t file of this patent:

UNITED STATES PATENTS Myracle. Apr... 8,, 1.94%- 

